1. Field
The present disclosure relates to paper tubes, and more particularly, to paper tubes with a corrugated paper layer, method of making of paper tubes, machines for making paper tubes.
2. Discussion of the Related Technology
References which disclose paper tubes are as follows: International Publication No. WO 97/13695, published on Apr. 17, 1997, entitled “METHOD AND DEVICE FOR PRODUCTION OF TUBES”; Korean Patent Laid-Open Publication No. 10-2002-0038467, published on May 23, 2002, entitled “POLYGONALLY WRAPPED PAPER PIPE MAKING MACHINE”; U.S. Pat. No. 4,120,323, issued on Oct. 17, 1978, entitled “POLYGONALLY WRAPPED SLEEVE AND METHODS AND DEVICES FOR MAKING SAME”; Japanese Patent Laid-Open Publication No. (Sho) 50-91808, published on Jul. 22, 1975, entitled “METHOD OF MAKING POLYGONALLY WRAPPED PAPER TUBE”.
Instead of a pallet made from used wood or synthetic resin, a pallet made of paper has been recently developed and used in the transport of freight. In general, a paper pallet comprises an upper plate on which freight is placed, and a support member which is attached to a lower surface of the upper plate to support the upper plate. As a support member of a paper pallet, a paper tube having a quadrangular cross section is widely used.
Methods and apparatuses for manufacturing a paper tube having a quadrangular cross section are disclosed in International Publication No. WO 97/13695, Korean Patent Laid-Open Publication No. 2002-0038467 and Japanese Patent Publication Laid-Open No. (Sho) 50-91808. The apparatus for manufacturing a polygonally wrapped paper tube disclosed in the aforementioned patent documents causes a plurality of paper strips previously coated with adhesive to be supplied to a rotating core having a quadrangular cross section and to be wound on an outer peripheral surface of the core. The apparatus is also provided with a plurality of rollers rotating about a rotational axis of the core at the same angular velocity as the core, wherein the plurality of rollers press the strips wound on the outer peripheral surface of the core and simultaneously rotate in a longitudinal direction of the core (rotate about the rotational axis perpendicular to the longitudinal direction of the core). That is, the apparatus for manufacturing a polygonally wrapped paper tube uses the principle that when a plurality of the rollers rotate in the longitudinal direction of the core while pressing the strips (paper tube) wound on the core, the paper tube wound on the core is separated from the core and discharged in the longitudinal direction of the core if a friction force generated between the rollers and an outside surface of the paper tube is greater than that generated between the core and an inside surface of the paper tube.
According to a method for manufacturing a quadrangularly wrapped paper tube disclosed in U.S. Pat. No. 4,120,523, a quadrangularly wrapped paper tube is manufactured by successively forming a circularly wrapped paper tube, which is continuously formed and discharged, to have a quadrangular cross section using a plurality of forming rollers.
The foregoing discussion is to provide general background information, and does not constitute an admission of prior art.